The invention relates to herbicidally effective compositions, and particularly to those that include naturally occurring active ingredients.
Many herbicides are known and used in agricultural, commercial and household applications to control and/or eliminate a variety of unwanted weeds and other plants. Historically, the most effective and widely used herbicides are petrochemical-based products. Although effective herbicides, these compounds have come under close scrutiny because some can be harmful to humans and other animals.
Herbicides and other pesticides have more recently been formulated from naturally occurring active ingredients such as fatty acids or fatty acid salts. Some herbicides use fatty acids and fatty acid salts as co-active ingredients with other compounds. Examples of such compositions are disclosed in British Patent No. 2,247,621 and U.S. Pat. Nos. 4,774,234; 4,975,110; 5,035,741; and 5,106,410.
Herbicides are commonly applied to driveways, sidewalks, patios, walls, and similar structures to eliminate any weeds or mosses growing in joints or cracks in such structures. Certain known fatty acid and fatty acid salt herbicides can leave behind an unsightly white residue when applied to these substrates. Such known herbicides, although chemically effective, have been a major source of customer complaint because they leave behind an aesthetically unpleasing residue.
There is thus a need for herbicidal compositions that are effective to control weeds, without leaving behind unsightly residue on substrates to which the compositions are applied.